Speed indicator



F. C. HARRIS.

SPEED INDICATOR. APPLICATION FILED FEB. 2, 192.0.

1,404,850, Patented Jan. 31, 1922.

Maw M Arm/ems).

UNITED STATES" PATENT OFFICE.

ERANK C. HARRIS, OF FAIRFIELD, IOWA.

' SPEED INDICATOR.

Specification of hetters Patent. 1 Patented J- 31, 1922 Application filed February 2, 1920. Serial No. 355,654. 7

To all whom it may concern: I Be it known that I, Fulani; C. Harris, a

citizen. of the United States, residing at Fairneld, 1n the county of State of Iowa, have invented a new and use- Jefferson ang.

iul Improvement in Speed Indicators, of

' which the following is a Specification.

My invention relates to an improved speed indicator for indicating the speedoi' moving vehicles by devices actuated by a moving partof the vehicle or m'ore broadly for indicating the speed of operation or rotation.

s rin s or the e uivalent which )ositi'velv,

make and break electrical contact'ina ma n ner to produce alternating impulses of current flow through the circuit controlling the 7 operation of the indicating pointer or other is not maintained accurately with said commutators owing to the jumping of the device, as distinguished from rotating commuta-tors which have been proposed heretofore for this purpose and which have been found inefficient for the reason that contact brushes.

My invention will best be understood by reference to the accompanying drawings showing a preferred embodiment thereof, in Whichp 1 is a diagrammatic view of my im proved indicating mechanism and the devices employed to actuate the same together with the circuit connections used to connect the indicating mechanism with the actuating devices. 7 y r Fig. 2 .is a side elevation of' the actuating devices shown in Fig. 1 and v Fig. 3;shows in a view similar to Fig. 1 a modified form of indicating mechanism operated by my improved actuating devices. Similar numerals refer to similar parts throughout the several views. 7

As shown inFig. 1 the indicating mech anism consists or a pointer 10 pivotally sup ported at 11 and a scale 12 disposed adjacent the indicating end of the pointer for indicating the speed of operation of the device whose speed is to be measured. The lower end of the pointer 10 is continued beyond its pivot lland carries two curved c0res13 and 1 for the solenoids 15 and 16 1'espective'ly.

The actuating mechanism employed for operating the ind cating devices consists of a reciprocating member 17 mounted in suitable bearings 18 which carriesat its upper end as shown n F g. 1 two rollers 19 and 20 engaging opposite SldGS Of a cam 21 of circular conformation which is .eccentrically mounted'on a shaft 22 rotatablymounted in bearings 23, whichshaft is connected in any desired 'manner with the moving parts the speed of which it is desired to measure. The

bar 17 has projecting therefrom two insulating studs 24: engaging opposite sides of a spring contact-25 supported at 26 and also two insulating studs. 27 similarly engaging a second spring contact 28 supported at 29.

Contacts 30 and 31 are associated with the springcontact 25 and similar contacts 32 and 33 are associated with the spring contact 28 in such a manner that when, the bar 17 is moved upwardly by rotation of the cam 21, said spring contacts 25 and 28 engage s respectively the contacts 30 and 32 and when said bar is moved downwardly by the action of said cam said spring contacts engage respectively the contacts 31'and 33. A spring 31 is disposed between the lower end of the bar'17 and a fixed abutment 35 to compensate for-the weight of the bar and relieve the 7 strain on thercam 21 as it rotates.- Where the rate of rotation of the shaft 22 is not great, the roller 20 may be omitted and the spring 3e alone relied upon to maintain the roller 19 in engagement with the surface of the cam 21. V y

The terminals of the solenoids 16 are connected by wires 36 and 37 with the respectacts 31 and. 32 are connectedtogether by wire 4L1 and this wire is connected by 'Wire 42 with one terminal of the solenoid 15." The contacts 30 and 38 v are connected together by wire 43 which wire is connected by wire 44 with one terminaloif the impedance coil 45,

' the other terminal of which is connected by Inoid-15.

cated, it will be observed that when the contact springs 25 and28'are in their lower 7 position as indicated in Fig. 1, current flows from the battery'38 through the solenoid through the following path: battery 38, wire '36,"wire' 39, contact spring 25, contact 31-,

wire 41, wire 42, solenoid 15, wire 46, im-

pedance coil45,wire 44, wire 43, contact 33, contact spring 28, 'wire'lO, wire 37, baclr to battery 38. VVhen' the contact springs and 28 are moved upward away from the J contacts 31' and33, the circuit'just traced is interrupted and a second circuit is closed'as follows from batteryi38 battery 38, wire 36,-

wi're39, contact spring 25, contact 30, wire 44, impedance (3011 425, wire 46, solenoid 15,

' wire 42, wire 41, contact 32, contact spring.

. opposite in direction and producing in coil 45jis so proportioned "andithe rate of operationfof the bar 17 is preferably high} 28, wire 40, wire 37, back to battery1Z-3S.

iFrom the circuit just ti'aced it" will appear that'for each cycle of operation of the bar" 17; two impulses'are sentithrough the winling of the solenoid 15 said impulses being efiect anl alternating current flow through the winding of the solenoid. The impedance enough for the slowest rate to be indicated bythepOinter 10 that the impedance coil exerts a} retarding effect upon the alternatingcurrent passing through it proportional.

to the speed of the device to be measured,

7 as aresult of which as the rate of the alternations or the frequency of the alternating current s increased the amount of current i flowing throughthec solenoid 15 will bedecreased, sinceit is to be borne ininind that a constantfelectromotive force is impressed upon the circuit of the solenoid ISby-th'e twillalso be observed that battery-138. the solenoidleis energized by direct curforce isimpressedby saidsolenoid upon the core 14. In this manner a differential action -1S produced upon the cores 13 and 14 which 7 serves to' move vthe pointerffrom one posiglhich current is inversely proportional to e this shaft, The solenoids'le tionftoano'ther between its positions of eX- treme movement depending upon the amount of current flow through the solenoid 15,

e eedpr operation of the shaft 22. i In 7 l n l" for indicating the speed ofrotation of said andfl6 are so proportioned-"that Iwhen thefcurrent flowing rth'rouglijtheisolenoid15is ofthe value de termined lowest speedof operation offthe shaft 22 to be'mea'sured," the result The scale'12'is' then calibrated so as to corithe solenoid 16 is omitted in thisfconstrum this construction the solenoidle is con nected to the contacts associated fwithjthe an accurate means is provided of the magneticaction upon the cores '13 and 14 is such as to moveithef pointer 10" to nearly its zero indication on'the scale 12;

rectly indicate other speeds'of the shait221 for otheramounts of the difi erential' action of the solenoids 15 and 16 referredto} In the construction shown in Fig. 3, substantially the same actuating devices are eni-fployed, the only difierence being that the battery 38"has "its terminals directly connected by wires 39' and eOfwith the contact springs 25 and 28, all other circuit connections from the battery being removed, since, I

tion and replaced by a spring 47 acting upon the pointer 10 to exert. a similar varying pull thereon in opposition to the' mag-f netic pull exerted by the solenoid- 15.- ln."

contact'springs 25 and 28in the same man ner as described above and .the'rdevice i 1 1 operated in substantially the same manner to indicate the speed of rotation of the shaft 22 or other moving parts usedtogreciprd cate' thefbar17." 1 From the abovejit will appear. thatl have j provided an improved actuating'nieans for speed indicators by which i an alternating variations in the speed; of the 7 device to be measured. And iurtherniore .loyfmy; im 7 proved construction I provide means 103 which the alternating currentthusproduced be" measured; 2 i 7 While I have shownmyinventioniiin the f particular embodiment .above dcscribed I do not however limit myself to this exact con l struct1on in carrying out my invention as 1 A may employ equivalents thereofknown to p v the art at the time of the filing of this appli 2 rent flow of constant electromotive force as" a result of which a'constant' magnetomotive the appended claims.

- VVhatTI claim is: i 1. In a speed indicator the combination" of; a reciprocable member, two contact cation without departing'from' the scopeof nected with said springs, a solenoidthavingi one terminalofits winding connected with or V the outer contacts or said springs and havf ing its other terminal connected"with-;1the

inner contacts of said springs, an imped ance 0011' connected n c rcuit withysaid solenoid between said solenoid and sa dcon- V jtacts', and an iii'dicator operatedbv said solenoid,- s id member adapted to bef actu 95 current may be accurately 'ancbdefinitelyf V, produced, varying 1111'9138101 frequency with V V ated by mechanism the speed of which is to be indicated, whereby the displacement of said indicator from its zero position is proportional to the rate of operation oi said member.

2. Ina peed indicator, the combination of a source of direct current, pole changing device's comprising contact springs and contacts connected with said source, and an indicator and impedance'coil connected in circuit with said pole changing devices, said pole changing devices adapted for operation by mechanism the speed of which is. to be indicated.

3. In a speed indicator, the combination of two current reversing contact springs, two'contacts for alternate engagement with each contactsprmg, mechanism tor simultaneously producing contact between said source of springs and said contacts alternately, a source of direct current and an indicator connected with said contacts and springs, said indicator being responsive proportionally to the frequency of the alternating urrent supplied to it, and devices the speed I nections between said bar and said contact springs.

In a speed indicator, the combination of two current reversing contact springs, two contacts for alternate engagement with each contact spring, mechanism for simultaneously producing contact between said springs and said contacts alternately, a source of direct current and an indicator connected with said contacts and springs,

said indicator being responsive proportion ally to the frequency of the alternating current supplied to it, and devices the speed of which is to be indicated for operating said mechanism, said mechanism comprising a reciprocating bar, insulating connections between said bar and said contact springs, a cam "for moving said bar in one direction and a spring for moving said bar in the reverse direction, said cam being actuated by said devices. 7

6. In a speed indicator, the combination of two current reversing contact springs, two contacts for alternate engagement with each, contactsprin mechanism for siinul a! taneously producing contact between sa d springs and said contacts alternately, a

source of direct current and an indicator connected with said contacts and springs, said indicator being responsive proportionally to the frequency of the alternating current supplied to it, and devices the speed of which is to be indicated for operating said mechanism, said mechanism comprising a reciprocatingbar, insulating connections between said bar and said contact springs, and a cam for positively movin aid bar alternately in opposite directions, said cam being actuated by said devices.

7. In a speed indicator, the combination of two current reversing contact springs, two contacts for alternateengagement with each contact spring, mechanism for simultaneously producing contact between said springs and said contacts alternately, a source of direct current and an indicator connected with said contacts and springs, said indicator being responsive proportionally to the frequency of the alternating cur rent, supplied to it, and devices the speed of which is tobe indicated for operating said mechanism, said mechanism comprising a reciprocating bar, insulating connections between said bar and said contact springs, a

.cam for moving said bar in one direction a spring for moving said bar, in the reverse direction, said cam being actuated by said devices, and a roller carried by said bar engaging said cam.

8. In a speed indicator, the combination of two current reversing contact springs, two contacts for alternate engagement with each contact spring, mechanism for simultaneously producing contact between said springs and said contacts alternately, a-

source of direct current and an indicator" connected with said contacts and springs, said indicator being responsive proportionally to the "frequency of the alternating current supplied to'it, and devices the speed of which is to be indicated for operating said mechanism, said mechanism comprising a reciprocating bar, insulating connections between said bar and said contact springs, a cam for positively moving said baralternatcly in opposite directions, said cam being actuated by said devices, and rollers carried by said bar on opposite sides of and engaging said cam.

9. In a speed indicator, the combination of indicating devices, a movable magnetic member connected with said devices, an electromagnetic winding for exerting an attraction upon said member inversely proportional to the frequency of alternating current flowing through said winding, means tending to move said member from said winding, a circuit extending from said winding including an impedance coil in series thereimwvliereby supplying said cit cui't with an alternating cui'rentlof a fre -quency proportional t9 the'speed 0 f the device to be indicated results in movement of said member from said winding and cc'irespending moYement of said 1ndicat1ng devices. as the' frequency of said alternating current increases.

memberconnected with said'devices, an electrcma neticwindin for exertin an attrac O t) b tion 'upcn said member inversely proportional to thefi'equenq of alternating cul rentj flowingthrough said Winding, means tending to move said member from 'said 10. In a speed indicat6r,.tl1e combination of indicating devices, ajmova-ble magnetic Winding, a circuit extendingi'i'omsaid Wind ing including an impedance coil in series therein, whereby supplying said circuit with an alternating current of a frequency proportional to the speed of the device to be indicated results n movement of said memher from said winding and corresponding movement of said indicating devices as the frequency of said alternating current increases, said means consisting of a uniformly and constantly energized electromagnetic Winding:

V In Witness whereof I hereuntc siibscribe V my name this 30th day 701" January A. D. 30

FRANK ci iiiiiinis. g 

